diff --git a/src/honey/sql.cljc b/src/honey/sql.cljc
index b67fd85..9c829e8 100644
--- a/src/honey/sql.cljc
+++ b/src/honey/sql.cljc
@@ -31,7 +31,7 @@
   (:require [clojure.string :as str]
             #?(:clj [clojure.template])
             [honey.sql.protocols :as p]
-            [honey.sql.util :refer [str join]]))
+            [honey.sql.util :refer [str join split-by-separator]]))
 
 ;; default formatting for known clauses
 
@@ -316,7 +316,7 @@
                             [n %]
                             (if aliased
                               [%]
-                              (str/split % #"\."))))
+                              (split-by-separator % "."))))
          parts       (parts-fn col-e)
          entity      (join "." (map #(cond-> % (not= "*" %) (quote-fn))) parts)]
      (suspicious-entity-check entity)
@@ -457,7 +457,7 @@
                 :default (subs (str x) 1))
              (str x))]
      (cond (str/starts-with? c "%")
-           (let [[f & args] (str/split (subs c 1) #"\.")]
+           (let [[f & args] (split-by-separator (subs c 1) ".")]
              [(str (format-fn-name f) "("
                    (join ", " (map #(format-entity (keyword %) opts)) args)
                    ")")])
diff --git a/src/honey/sql/util.cljc b/src/honey/sql/util.cljc
index 1e621ad..471e7c4 100644
--- a/src/honey/sql/util.cljc
+++ b/src/honey/sql/util.cljc
@@ -75,3 +75,16 @@
 
       :default
       (clojure.string/join separator (transduce xform conj [] coll)))))
+
+(defn split-by-separator
+  "More efficient implementation of `clojure.string/split` for cases when a
+  literal string (not regex) is used as a separator, and for cases where the
+  separator is not present in the haystack at all."
+  [s sep]
+  (loop [start 0, res []]
+    (if-let [sep-idx (clojure.string/index-of s sep start)]
+      (recur (inc sep-idx) (conj res (subs s start sep-idx)))
+      (if (= start 0)
+        ;; Fastpath - zero separators in s
+        [s]
+        (conj res (subs s start))))))
diff --git a/test/honey/util_test.cljc b/test/honey/util_test.cljc
index 7ee6f6c..1cc1f2e 100644
--- a/test/honey/util_test.cljc
+++ b/test/honey/util_test.cljc
@@ -43,3 +43,11 @@
   (is (= "1, 2, 3, 4"
          (sut/join ", " (remove nil?) [1 nil 2 nil 3 nil nil nil 4])))
   (is (= "" (sut/join ", " (remove nil?) [nil nil nil nil]))))
+
+(deftest split-by-separator-test
+  (is (= [""] (sut/split-by-separator "" ".")))
+  (is (= ["" ""] (sut/split-by-separator "." ".")))
+  (is (= ["hello"] (sut/split-by-separator "hello" ".")))
+  (is (= ["h" "e" "l" "l" "o"] (sut/split-by-separator "h.e.l.l.o" ".")))
+  (is (= ["" "h" "e" "" "" "l" "" "l" "o" ""]
+         (sut/split-by-separator ".h.e...l..l.o." "."))))